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From: rsfinn@CONCERTO.LCS.MIT.EDU (Russell S. Finn)
Newsgroups: comp.sys.mac.system
Subject: Re: System 7 re-verify
Message-ID: <1991Apr10.221317.10619@mintaka.lcs.mit.edu>
Date: 10 Apr 91 22:13:17 GMT
References: <kc0kcZm00WB7I2BUwF@andrew.cmu.edu>
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In article <kc0kcZm00WB7I2BUwF@andrew.cmu.edu>, jp48+@andrew.cmu.edu (Jonathan Pace) writes:
|> 
|>    I just erased a disk that was giving me problems and I watched the usually
|> boring description of what was happening.  Thing is, system 7 (b4) said it
|> was re-verifying the disk at one point.  It took about as much time as the
|> normal verify, which it also did.
|> 
|>    Is this a feature that it does all the time, or is it just used on disks
|> that are giving screwy verification results?

Congratulations, you've just discovered the new "block-sparing" feature
of System 7, described in one of the most recent batch of Tech Notes.
Under System 7, the Disk Initialization Package can detect certain
errors when formatting disks and mark those sectors so that they are
not used.  (I believe it only attempts this on floppy-sized disks,
under the assumption that good hard disk drivers already do something
like this anyway.)  When this happens, the Finder displays the
"Re-verifying" message.  

Disclaimer:  This is based on a cursory reading of the Tech Note in
question, which I no longer have a copy of.  Perhaps someone would
like to expand on this.

-- Russell Finn
rsfinn@lcs.mit.edu